The present invention relates to a safety device in accordance with the preamble to claim 1.
For safety reasons, the speed of an elevator car must be monitored in order to be able to initiate emergency braking in the case of any failure. This is carried out nowadays according to the state of the art by a speed governor which operates mechanically, is driven by a cable and triggers a braking device, such, as for example, a safety gear, via cables and rods in the case of an approximately 20% overspeed.
This system does, however, originate from the founder times of elevator construction and is inexact, liable to failures, triggers only with a certain delay and operates, in particular, in the case of soiling, aging as well as inadequate maintenance only unsatisfactorily.
For this reason, regular safety gear operation tests are prescribed for elevator cars which do, however, represent an unnecessary extreme load on the elevator, negatively impair its safety in the long term or can even lead to a destruction of important components of the elevator, such as, e.g., the gearing. In addition, it is a disadvantage of the mechanical speed governors known from the state of the art that, generally, it is hardly possible to reconstruct the procedure for the triggering of the safety gear.
It is, therefore, the object of the present invention to make a safety device available which avoids these disadvantages from the state of the art and, in particular, increases the safety of the systems monitored by the safety device. In addition, the operation and the construction of the safety device are intended to be more convenient or rather simpler. In particular, as short a reaction time as possible and a precise triggering of the safety device are also intended to be realized. An improved scope of design for the systems is also intended to be realized as a result of the increased safety of the monitored systems.